Development of an Efficient Cardiac Auscultation System Using Proper Denoising Techniques

Heart auscultation is a primary and cost-effective form of clinical examination of the patient. PCG signal is used as a diagnostic test for evaluating the status of the heart and it helps in identifying related diseases. There are several limitations and practical problems in the human auditory system when it comes to phonocardiogram (PCG) signal analysis in a clinical environment, despite the cognitive skills and expertise of the medical examiner. Thus, the assessments provided by cardiac auscultation are subjective and sometimes provide an inaccurate diagnosis. The objective of this research is to develop an efficient heart auscultation system by implementing necessary pre-processing and suitable filtering techniques. The problem of controlling the noise level has been one of the research topics over the years. The various filters used are IIR Butterworth and Chebyshev digital filters, FIR filters, LMS filter, Wiener filter, Wavelet transform based filter and cascading of these filters were also done and the filter which gives the highest value of SNR and good tone audibility score is chosen as the most efficient filter for noise removal. Based on the performance comparison of various filtering technique and calculation of heart rate, an efficient heart auscultation system is developed to assist medical practitioners in PCG signal analysis.